The Union Church of San Juan is an interdenominational Christian church located in Punta Las Marías, San Juan. Founded in the early 20th century (around 1916–1917 through the merger of Methodist and Presbyterian congregations), it serves as one of the main English-speaking Protestant churches in Puerto Rico.

The church is centered on the belief in Jesus Christ as Savior and Lord and brings together Christians from a wide range of denominational backgrounds. Its mission emphasizes unity in the Christian faith, hospitality, and service to both the local and international community living in Puerto Rico.

Worship services are primarily conducted in English, with some Spanish integration, reflecting its multicultural congregation. The church is known for its welcoming environment that includes long-term residents, expatriates, military families, and visitors. Services typically feature traditional and contemporary worship elements, Bible-based preaching, choir music, and community participation.

A key aspect of Union Church is its commitment to inclusivity and reconciliation—creating a space where cultural, linguistic, and denominational differences are bridged through shared Christian faith. The church also supports various ministries such as education programs, small groups, outreach efforts, and community service initiatives aimed at serving both the congregation and the broader Puerto Rican community.

Overall, it functions as a stable, historically rooted, and multicultural church community focused on worship, spiritual growth, and unity among believers in an English-speaking setting within San Juan.